Amazon is working to extend Google's UCP protocol to support marketplaces, like
By Juozas · November 4, 2026 · Curated by George's Blog
Amazon is working to extend Google's UCP protocol to support marketplaces, like Amazon. No idea when any of this is going to go live or indeed whether Amazon wants that for automated buying from other marketplaces rather than making its catalog available to agents.
Universal Commerce Protocol is the protocol all agents use for commerce. It is open source so we get to see a lot of the features before they go live on say Gemini. Amazon's Greg Smith joined UCP's tech council back in April and these are his most recent contributions.
His 939 pull request opens with "when a marketplace or multi-entity global brand serves catalog items and checkouts, platforms need a consistent, low-latency way to represent both the storefront brand and the specific seller or legal entity behind each offer and transaction." The later 1018 pull request "adds response-normalized seller attribution across Cart, Checkout, and Order responses so multi-entity global brands and multi-seller marketplaces can resolve, disclose, and snapshot the authoritative contracting seller for a transaction and its line items."
This draft work is extending UCP from single-brand/single-seller storefronts like Shopify websites to multi-seller and/or multi-entity commerce, with marketplaces as the best example. Despite it being open source we don't get to see the full process, but we know this work originates from TikTok's requests.